All free online calculator tools
A growing collection of focused calculators for math, school, science, money, home projects, shopping, and everyday planning.
Popular categories
Use category hubs to find related calculators faster.
Basic Math
Fast calculators for percentages, rounding, unit rates, LCM, GCD, and long division.
Geometry
Calculate circle, triangle, coordinate, and volume problems with clear formulas.
Statistics
Probability, significance, normal distribution, standard deviation, and measurement-error calculators.
Linear Algebra
Matrix and vector calculators for dot products, determinants, eigenvalues, RREF, and cross products.
Finance
Investment, dividends, margin, military housing, discount, and money planning calculators.
Shopping
Compare deals, discounts, unit rates, tips, and real purchase totals.
Home & Construction
Estimate material volumes, project costs, TV mounting height, and home planning measurements.
Education
Student-focused calculators for GPA, AP scores, study checks, and academic planning.
Calculator directory
71 tools, each with category tags and a dedicated page.
LCM and GCD Calculator
Find the least common multiple or greatest common divisor of up to 5 numbers.
Long Division Calculator with Steps
Divide whole numbers with quotient, remainder, decimal expansion, and step-by-step work.
Number Rounding Calculator
Round numbers to any place value.
Percent Change Calculator
Find percent increase, percent decrease, original value, and final value.
Percentage Calculator
Calculate percentage of a number, percentage change, and common percent problems.
Circumference Calculator
Calculate circle circumference using radius or diameter.
Inverse Tangent Calculator
Compute arctan(x) in degrees and radians with quick exact values.
Midpoint Calculator
Find the midpoint, distance, or missing endpoint between two coordinate points.
Pythagorean Theorem Calculator
Calculate missing sides of right triangles.
Rectangle Volume Calculator
Calculate box volume, dimensions to liters, or a missing side from target volume.
Slope Calculator
Find slope from two points, get line equations in slope-intercept and point-slope form.
Volume Calculator
Calculate volume of rectangular objects with multiple units.
Convolution Calculator
Convolve two discrete sequences with start indices and overlap tables.
InvNorm Calculator
Find z-scores, critical values, and normal-distribution cutoffs from percentiles and confidence levels.
P-Value Calculator
Calculate statistical significance with Z-test, t-test, F-test, correlation, and chi-square tests.
Percentage Error Calculator
Compare observed and true values with signed and absolute percent error.
Standard Deviation Calculator
Calculate population and sample standard deviation, variance, and mean.
Cross Product Calculator
Compute 3D vector cross products, magnitude, and direction.
Eigenvalues & Eigenvectors Calculator
Find eigenvalues and eigenvectors of square matrices.
Matrix Determinant Calculator
Calculate the determinant of square matrices up to 4x4 with detailed steps.
Matrix Dot Product Calculator
Calculate the dot product of two matrices with step-by-step visualization.
RREF Calculator
Reduce matrices to row reduced echelon form with Gauss-Jordan steps.
BAH Calculator
Calculate your Basic Allowance for Housing (BAH).
Dave Ramsey Investment Calculator
Compare monthly investing scenarios with Ramsey's 12% return assumption.
Dividends Calculator
Project dividend income, DRIP reinvestment, taxes, and portfolio value.
Future Value Calculator
Calculate the future value of investments.
Margin Calculator
Calculate profit margin, markup, target selling price, and target cost.
Discount Calculator
Calculate sale prices, percentage off, and savings.
Tip Calculator
Calculate restaurant tip, split bills, and reverse-calculate bill amount from total paid.
Unit Rate Calculator
Find cost per unit and compare which option is the better deal.
Gravel Calculator
Estimate gravel volume, cubic yards, weight, and material cost.
Mulch Calculator
Estimate mulch cubic yards, bags, coverage, and material cost.
TV Wall Mount Height Calculator
Calculate optimal TV mounting height.
AP Score Calculator 2026
Estimate AP 1-5 scores for AP Lang, Chem, Bio, Calc, APUSH, Stats, and more.
GPA Calculator
Calculate your Grade Point Average.
Molarity Calculator
Calculate molarity, dilution, moles, mass, and solution volume.
Significant Figures Calculator
Calculate significant figures with mathematical expressions.
Acceleration Calculator
Calculate displacement, velocity, acceleration, and time.
Age Calculator Between Two Dates
Calculate exact age between any start date and target date.
Age Difference Calculator
Calculate the exact age gap between two people from birth dates.
End Behavior Calculator
Find left-end and right-end behavior for polynomial functions.
Factoring Calculator
Factor common single-variable polynomials with integer coefficients.
Function Table Calculator
Generate tables of values from equations or x-value lists with difference checks.
Partial Fractions Calculator
Decompose proper rational functions into partial fractions with coefficient-solving steps.
Concavity Calculator
Find concave up and concave down intervals, sign changes, and candidate inflection points.
Simpson's Rule Calculator
Approximate definite integrals from f(x) or equally spaced table values.
ACFT Calculator
Calculate your Army Combat Fitness Test score.
Astrology Sign Calculators
Browse free astrology sign calculators for birth chart placements and relationship points.
Birth Chart Compatibility Calculator
Estimate relationship compatibility from two birth dates, optional times, and locations.
Chiron Sign Calculator
Estimate your Chiron sign, healing pattern, and growth practices.
Composite Chart Calculator
Estimate a relationship chart signature, house focus, and blended love dynamic from two birth dates.
Dominant Planet Calculator
Estimate your chart's dominant planet with a planetary score breakdown and interpretation.
Hebrew Gematria Calculator
Calculate Hebrew Gematria values for words and phrases.
Height Predictor Calculator
Predict child's adult height based on parents' heights.
Juno House Calculator
Estimate your Juno house and where commitment themes show up most.
Juno Sign Calculator
Estimate your Juno sign and relationship compatibility style.
Lilith Sign Calculator
Estimate your Lilith sign, shadow themes, attraction patterns, and boundary lessons.
LMSYS Chatbot Arena Leaderboard
Explore historical Chatbot Arena ELO rankings, model streaks, and company trends.
Moon Phase Compatibility Calculator
Compare two birth moon phases and estimate emotional rhythm compatibility.
Moon Sign Calculator
Estimate your Moon sign, lunar phase, emotional style, and chart context.
North Node Calculator
Estimate your North Node sign, South Node pattern, and growth direction.
Part of Fortune Calculator
Estimate your Part of Fortune sign, house focus, and ease pathway.
Rising Sign Calculator
Estimate your rising sign or ascendant from birth time and location context.
Saturn Return Calculator
Find estimated Saturn Return dates, peak windows, and life-stage themes from your birth date.
Steps to Miles Calculator
Convert steps to miles or miles to steps using height, stride, pace, and calories.
Sun Moon Rising Sign Calculator
Estimate your Big Three astrology signs: Sun, Moon, and Rising.
Sun Sign Calculator
Find your Sun sign, date range, element, modality, and cusp context.
Venus Sign Calculator
Estimate your Venus sign, attraction style, and love values.
Vertex Calculator Astrology
Estimate your Vertex sign, Anti-Vertex axis, and relationship encounter themes.
Weight Loss Calculator
Plan weight loss by date with calorie deficit, percentage, protein, and macros.
Zodiacal Releasing Calculator
Estimate Lot of Spirit or Fortune timing periods with current-period and watch-point highlights.